WALNUT CREEK — After arresting a school custodian on suspicion of child molestation, police on Friday released his photo to see if other victims or witnesses might step forward.

Detectives arrested 44-year-old John Astor about 7 p.m. Thursday near his home on Jones Place in Walnut Creek, after investigating a molestation allegation brought to the Walnut Creek Police Department earlier this week.

Astor is suspected of molesting a boy younger than 14 in Walnut Creek within the past week, Detective Sgt. Jay Hill said. He would not be more specific, he said, to protect the identity of the victim. Astor had not met the victim at any of the schools where he worked, Hill added.

Astor remained in County Jail in Martinez on Friday in lieu of $1.5 million bail.

“He first came to our attention a couple months ago,” Hill said, in connection with another report of a molestation that allegedly occurred about a decade ago. “The victim (in that case) is an adult, and the alleged molestation occurred in San Francisco. So we forwarded the case to them.”

But a fresh call arrived Tuesday or Wednesday, he said. Based on the evidence gathered, police received an arrest warrant and searched Astor’s home. Astor works as a custodian for the Mt. Diablo Unified School District, police said. Hill said he appears to work at several campuses in the district, but he awaits further information from district administration.

Police know of two potential victims, Hill said. But because of Astor’s access to children, Walnut Creek police want to hear from anyone who has information about Astor, or suspects their child might be a victim. Police ask witnesses or potential victims to call 925-943-5844.